Sodium hypochlorite

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The recovered amount of test material appears to be low. However, results of the study provide valuable information on the toxicokinetics of the test material.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1983

Materials and methods

Objective of study:

metabolism

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 417 (Toxicokinetics)

Deviations:

not specified

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium hypochlorite

EC Number:

231-668-3

EC Name:

Sodium hypochlorite

Cas Number:

7681-52-9

Molecular formula:

ClO.Na

IUPAC Name:

sodium hypochlorite

Details on test material:

Sodium hypochlorite (radiolabelled, 36Cl, 0.45 µCi)

Radiolabelling:

yes

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

Concentration in vehicle: 250 mg/L
Specific activity: 0.45 µCi
Total volume applied: 3 mL

Doses / concentrations

Remarks:

Doses / Concentrations:
Males: 3.26 mg/kg bw

No. of animals per sex per dose / concentration:

Males: 12

Control animals:

no

Details on dosing and sampling:

Blood samples: 5, 10, 20 ,30, 60 minutes and 2, 4, 8, 24 and 48 hours.
All other samples: 72 hours (termination)
Tissues sampled: Specimens of stomach, testes, lung, kidney, duodenum, ileum, spleen, liver, bone marrow, carcass and skin.
Treatment of samples:
Blood samples were centrifuged at 1000g for 15 minutes to separate the red blood cells from the plasma
Whole blood and packed cells were prepared by the method of Mahin. Samples of wet tissue weighing up to 200 mg and samples of bone marrow up to 50 mg were placed in individual glass LSC vials. 2 mL Protosol was added to each vial, which was capped tightly to prevent loss of solvent. Samples were solubilised by heating overnight at 50 °C, and then cooled at room temperature; afterwards 0.2 mL of 30 % H2O2 was added for decolouration. The samples were heated at 50 °C for 30 minutes, and then cooled and 15 mL of Aquasol-2 was added.

Statistics:

Not stated

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on absorption:

The rate constants for absorption and elimination of hypochlorite were 0.157 and 0.009 h-1, respectively.

Details on distribution in tissues:

Hypochlorite was widely distributed in the body with highest values in plasma, followed by bone marrow, kidney, testes, lung, skin, duodenum, spleen, stomach, liver, carcass and ileum.

Details on excretion:

In the excretion study about 76 % of the recovered dose was found in the urine, 24 % in the faeces.

Toxicokinetic parameters

Test no.:

#1

Toxicokinetic parameters:

other: rate constant

Metabolite characterisation studies

Metabolites identified:

not measured

Any other information on results incl. tables

Distribution and excretion of hypochloric acid in the rat 72 hours after oral administration

Analysed material	Percentage of initial dose [%]	Standard deviation [%]
Body fluid, tissue
Plasma	0.77	0.04
Kidney	0.39	0.03
Lung	0.34	0.02
Stomach	0.20	0.03
Duodenum	0.28	0.04
Ileum	0.14	0.02
Liver	0.20	0.01
Spleen	0.23	0.02
Bone marrow	0.40	0.01
Testes	0.37	0.02
Skin	0.32	0.03
Carcass	0.18	0.003
Excreted material
Urine	21.52	2.51
Faeces	7.09	0.24
Expired air	not detected	n.a.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): no bioaccumulation potential based on study results
The rate constants for absorption and elimination of hypochlorite were 0.157 and 0.009 h-1, respectively. Hypochlorite was widely distributed in the body with highest values in plasma, followed by bone marrow, kidney, testes, lung, skin, duodenum, spleen, stomach, liver, carcass and ileum. In the excretion study about 76 % of the recovered dose was found in the urine, 24 % in the faeces.

Executive summary:

MATERIALS AND METHODS:
Sprague-Dawley rats were administered 3 mL of a radiolabelled hypochloric acid solution by gavage. Heparinised blood samples were collected 5, 10, 20 ,30, 60 minutes and 2, 4, 8, 24 and 48 hours after treatment by orbital sinus puncture. The radioactivity was counted, the rate constant and half-life of absorption were calculated. Another group of rats were treated similarly and sacrificed 72 hours after treatment. Blood and tissue samples were collected and examined for radioactivity content. Finally, a third group of rats were treated with 3 mL of a radiolabelled hypochloric acid solution and housed in metabolism chambers for the collection of expired air, faeces and urine. Total radioactivity in these samples was counted. Results: The rate constants for absorption and elimination of hypochlorite were 0.157 and 0.009 h-1, respectively. Hypochlorite was widely distributed in the body with highest values in plasma, followed by bone marrow, kidney, testes, lung, skin, duodenum, spleen, stomach, liver, carcass and ileum. In the excretion study about 76 % of the recovered dose was found in the urine, 24 % in the faeces.